Spectrophotometric determination of Metformin in pharmaceutical preparation using Prussian blue reaction.

The recent study aims to provide a new spectrophotometric technique for the determination of Metfmmin (Met) in its local pharmaceutical preparation. This method depends on the reacting ofMetformin (Met.) with FeCI3 and hexacyanoferate (III) in acidic medium to yield a colored product measurable spectrophotometrically at λ max =720 nm.The effect of various parameters such as nature and amount of acid used, concentration of K3Fe(CN)6 and FeCl3,temperature and time of reaction were investigated. Under optimum conditions linearity was found in the range (0.1-7) μg.m1 -1 with detection limit of (0.01) μg.m1 -1and the correlation coefficient (I= 0.999).The relative standard deviation was (1.25%) for Metformin which confirmed the reproducibility of the assay technique. For Metformin this method gave signifi.cantly more sensitive data compared with other methods.